A variety of systems and devices have been made and used for treating morbid obesity. Some such systems and devices include adjustable gastric band systems, which are operable to restrict the flow of food from the esophagus into the stomach. Some gastric bands include a fluid-filled elastomeric bladder with fixed endpoints that encircles the stomach just inferior to the gastro-esophageal junction. When fluid is added to the bladder, the band expands against the stomach, creating a food intake restriction or stoma in the stomach. To decrease this restriction, fluid is removed from the bladder. Examples of gastric bands are disclosed in U.S. Pat. No. 7,416,528, entitled “Latching Device for Gastric Band,” issued Aug. 26, 2008, the disclosure of which is incorporated by reference herein. Another example of such an adjustable gastric band is disclosed in U.S. Pat. No. 6,067,991, entitled “Mechanical Food Intake Restriction Device,” issued May 30, 2000, the disclosure of which is incorporated by reference herein.
To the extent that an adjustable gastric band system includes an injection port configured to receive the needle of a syringe assembly to add or withdraw fluid to or from the gastric band, those of ordinary skill in the art will appreciate that it may be desirable in some settings to locate both the injection port and, more specifically, the center of the injection port (e.g., when the septum of the injection port is at the center of the injection port). Locating the approximate center of the injection port with some degree of accuracy may facilitate addition or withdrawal of fluid via the injection port to adjust the gastric band system. One example of a system and method for identifying the location of an injection port is disclosed in U.S. Pub. No. 2006/0211914, entitled “System and Method for Determining Implanted Device Positioning and Obtaining Pressure Data” published Sep. 21, 2006, and issued Aug. 17, 2010 as U.S. Pat. No. 7,775,215, the disclosure of which is incorporated by reference herein.
Those of ordinary skill in the art will appreciate that it may be advantageous in certain circumstances to sense pressure, strain, and/or other parameters associated with operation of a gastric band device. In some settings, it may be desirable to obtain data indicative of the pressure of fluid in a gastric band. Various examples of methods and devices for obtaining pressure data and other types of data are disclosed in U.S. Pub. No. 2006/0189888, entitled “Device for Non-Invasive Measurement of Fluid Pressure in an Adjustable Restriction Device,” published Aug. 24, 2006, and issued Apr. 20, 2010 as U.S. Pat. No. 7,699,770, the disclosure of which is incorporated by reference herein. Additional examples of methods and devices for obtaining pressure data and other types of data are disclosed in U.S. Pub. No. 2006/0199997, entitled “Monitoring of a Food Intake Restriction Device,” published Sep. 7, 2006, and issued Sep. 13, 2011 as U.S. Pat. No. 8,016,745, the disclosure of which is incorporated by reference herein.  Such parameter data may be obtained before, during, and/or after adjustment of a gastric band, and may be useful for adjustment, diagnostic, monitoring, or other purposes, and may also be obtained with respect to a mechanically actuated gastric band. In settings where a fluid-filled gastric band is used, pressure data may be used to determine whether the amount of fluid in the gastric band needs to be adjusted; and/or for other purposes.
In some instances, it will be appreciated that gastric bands may be difficult to use as a result of slipping post-installation. For example, the user may install a gastric band at a particular location, only to have the gastric band later slip or roll to an undesirable location. Such inadvertent movement of the gastric band may cause undesirable results and/or suboptimal treatment with the gastric band.
While a variety of gastric band systems have been made and used, it is believed that no one prior to the inventor(s) has made or used an invention as described herein.
The drawings are not intended to be limiting in any way, and it is contemplated that various embodiments of the invention may be carried out in a variety of other ways, including those not necessarily depicted in the drawings. The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention; it being understood, however, that this invention is not limited to the precise arrangements shown.